#include <bits/stdc++.h>
// 2025/02/04
// tag: 
// Author: Zhang Muen
using namespace std;

using int64 = int64_t;

string a, b;

int dp[2001][2001];

signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cin >> a >> b;
    int n = a.size(), m = b.size();
    for (int i = 0; i <= n; i++)
        dp[i][0] = i;
    for (int i = 0; i <= m; i++)
        dp[0][i] = i;
    for (int i = 1; i <= n; i++){
        for (int j = 1; j <= m; j++) {
            if (a[i - 1] == b[j - 1])
                dp[i][j] = dp[i - 1][j - 1];
            else
                dp[i][j] = min(dp[i - 1][j], min(dp[i][j - 1], dp[i - 1][j - 1])) + 1;
        }
    }
    cout << dp[n][m];
    return 0;
}